The present invention relates to a common storage system shared by a plurality of terminal units and to an information processing system having the same and, particularly, to a common storage system for making a remote boot possible for those terminal units and to an information processing system having the same.
There is a mode, in which a plurality of terminal units shares a storage unit for storing an operating system (hereinafter referred to as “OS”) and an application program, by a network connection. The iSCSI (Internet Small Computer Systems Interface) protocol is known as connection method. The SCSI protocol for accessing the storage unit is used as a communication protocol on the network such as the Ethernet.
In case the terminal unit is provided with a remote boot function, the OS and the application program can be loaded from the storage unit having a control function. By connecting the terminal unit having the remote boot function and the storage unit through the iSCSI protocol, it is possible to realize a terminal unit, which need not be provided with an auxiliary storage unit. This terminal unit is called the “diskless terminal unit” or “diskless system”.
In case the kinds of the individual terminal units are different in the remote boot of the diskless terminal unit, OS programs for every kinds are prepared on the common storage unit. At remote boot execution, the terminal unit has to read out the OS program file matching the kind of the terminal unit. This method is exemplified by one using the MAC (Medium Access Control) address. The MAC address is assigned to the terminal unit, the common storage unit having the control function and a LAN board mounted on a server. In this method, more specifically, a plurality of OS program files placed over the common storage unit are matched with the kind of the terminal unit, the directory stored with the OS program file group for the kind of the terminal unit are discriminated, and the remote boot is done by using the OS program file group under the directory. This method is disclosed, for example, in Japanese Patent Application Laid-open No. H6-332716 and U.S. Pat. No. 240,955.
Like the general terminal unit, moreover, the terminal unit for executing the remote boot described above is allowed to use most OS software under a license contract. Here, the software means the OS and the application program. The license contract is coarsely classified into two kinds. One has a mode, in which the license contract is made by fixing the user so that the software is installed for use on an arbitrary terminal unit. In another method, a unit of software is purchased under a license by an enterprise. The enterprise is responsible for the users, the number of user licenses and of the terminal units. Especially in the latter case, the method for the user to use software without any consciousness and to provide the license is disclosed in Japanese Patent Application Laid-open No. 2002-006975, for example. If the stock of the license is examined and found exhausted in case the software is demanded by user, the method uses the software, as not installed yet, on the terminal unit and settles the payment automatically with little load on the manager by automating the newly purchasing procedure.